An inverstigation of effect of venturi weir type on air entrainment ratio

Aeration is a natural or mechanical process of increasing the contact between water and air for the purpose of releasing entrained gases, adding oxygen, and improving the chemical and physical characteristics of water. Hydraulic structures can be accepted as the key components in improving aeration efficiency because of the strong turbulent mixing associated with substantial air bubble entrainment at these structures. Weir is the most classic example of a hydraulic structure where aeration occurs and the aeration properties of such a structure has been widely studied in the laboratory and field over a number of years. The present paper investigates the effect of the venturi weir type on air entrainment ratio. The results indicate that the venturi weirs are highly effective in terms of air entrainment ratio but however, the venturi weir type do not have a significant effect air entrainment ratio. Moreover, regression equations are obtained for the venturi weirs relating air entrainment ratio to jet Froude number.Artificial intelligent methods are today extensively used in many areas. In this study was to develop a model, using artificial intelligent methods, for estimating air entrainment ratio in venturi weirs. For this aim, Adaptive Network based Fuzzy Inference Systems (ANFIS) and artificial neural network (ANNs) methods were used. The test results revealed that ANFIS model predicted the measured values at higher accuracy than ANNs model. Average correlation coefficients (R2) in ANFIS models were achieved equal to 0.9623 for ß = 0.75 and 0.9666 for ß = 0.50. Extremely good agreement between the predicted and measured values confirms that ANFIS model can be successfully used to predict air entrainment ratio in venturi weirs.Key Words: Air Entrainment Ratio, Venturi, Weir, ANFIS, ANN